c - 用户空间中的文件系统(FUSE)编译错误

/*This is a simple try to create a File System in UserSpace
The pre_init function just initializes the filesystem */
#include<linux/fuse.h>
#include<stdio.h>
#include<stdlib.h>
#include<fuse_lowlevel.h>


static void* pre_init(struct fuse_conn_info *conn, struct fuse_config *cfg){
        printf("[init] called\n");
        (void) conn;
        return NULL;
}
static struct fuse_operations opr = {
        .init = pre_init,
};
int main(int argc, char *argv[]){
        return fuse_main(argc, argv, &opr, NULL);
}

我正在尝试使用 gcc sample.c -o sample`pkg-config fuse --cflags --libs` 来编译代码我在代码中发现了很多错误

 sample.c:7:59: warning: ‘struct fuse_config’ declared inside parameter list will not be visible outside of this definition or declaration
 static void* pre_init(struct fuse_conn_info *conn, struct fuse_config *cfg){
                                                           ^~~~~~~~~~~
 sample.c:12:15: error: variable ‘opr’ has initializer but incomplete type
 static struct fuse_operations opr = {
               ^~~~~~~~~~~~~~~
 sample.c:13:3: error: ‘struct fuse_operations’ has no member named ‘init’
  .init = pre_init,
   ^~~~
 sample.c:13:10: warning: excess elements in struct initializer
  .init = pre_init,
          ^~~~~~~~
 sample.c:13:10: note: (near initialization for ‘opr’)
 sample.c: In function ‘main’:
 sample.c:16:9: warning: implicit declaration of function ‘fuse_main’; did you mean ‘fuse_mount’? [-Wimplicit-function-declaration]
 return fuse_main(argc, argv, &opr, NULL);
         ^~~~~~~~~
         fuse_mount
 sample.c: At top level:
 sample.c:12:31: error: storage size of ‘opr’ isn’t known
 static struct fuse_operations opr = {
                               ^~~

我还检查了 fuse 是否正确安装，因为头文件已包含在内，没有任何问题。但是为什么我不能编译这个简单的代码？

最佳答案

有两个“ fuse ”版本，有时彼此并存:fuse2和fuse3。他们不同。在我的Archlinux中，有两个 fuse 包:fuse2和fuse3。在我的系统上，文件/usr/include/fuse.h仅包含fuse/fuse.h，而fuse/fuse.h来自fuse2软件包。头fuse3/fuse.h来自fuse3。
无论如何，当您使用struct fuse_config时，您想在这里使用fuse3 api。 fuse3定义struct fuse_config。
但是，最需要的是，在包含任何 fuse 头文件之前定义FUSE_USE_VERSION宏，如fuse.h from fuse2开头和fuse.h from fuse3中所指定:

IMPORTANT: you should define FUSE_USE_VERSION before including this header.

以下代码在我的平台上使用gcc -Wall -pedantic -lfuse3 1.c进行编译，没有警告/错误:

#define FUSE_USE_VERSION 31
#include <fuse3/fuse.h>
#include <stdio.h>
#include <stdlib.h>

static void* pre_init(struct fuse_conn_info *conn, struct fuse_config *cfg){
        printf("[init] called\n");
        (void) conn;
        return NULL;
}
static struct fuse_operations opr = {
        .init = pre_init,
};
int main(int argc, char *argv[]){
        return fuse_main(argc, argv, &opr, NULL);
}

关于c - 用户空间中的文件系统(FUSE)编译错误，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/49704210/